$2\mathrm{.}2$ Identify which name in each of the following pairs is a legitimate MATLAB variable name:

$\backslash$table$[[$fred$,$fred!$],[$book$\_1,$book$-1],[2$ndplace,Second$\_$Place$],[$#$1,$No$\_1],[$vel$\_5,$vel. $5],[$tan$,$while$]]$

Test your answers by using isvarname$-$for example,

isvarname fred